Method and apparatus for oral hygiene

ABSTRACT

A method and apparatus for cleaning the teeth and massaging the gums are described in which a pulsating jet of liquid is pressure modulated, the modulation frequency being substantially lower than the frequency of the pulsations, and the modulated pulsating jet is directed against the surfaces to be treated. The pulsation frequency may be in the range of 600-6000 pulses per minute, and advantageously above about 3000, to clean the teeth effectively. The modulation frequency may be in the range of 70-600 cycles per minute, and advantageously less than about 300, to massage the gums effectively.

United States Patent n51 3,696,809 Moret [4 1 Oct. 10, 1972 [5 METHODAND APPARATUS FOR ORAL 3,227,158 l/ 1966 Mattingly ..128/66 HYGIENE3,401,690 9/1968 Martin ..l28/62 UX [72] Inventor: {Vlicjhel A. Moret,Geneva, Switzer- FOREIGN TE O APPLICATIONS an 1,225,547 2/1960 France..l28/62 A [73] Assrgnee: Instrtut De Recherche .Et De Diffusionlndustrielle P.G.E. Wood, Primary E i er L. W. Trapp Geneva, swltlerlandAttorney-Pennie, Edmonds, Morton, Taylor & 22 Filed: Aug. 12, 1969 AdamsI [211 Appl. No.: 849,464 [57] ABSTRACT A method and apparatus forcleaning the teeth and [30] For lgn App i ati n Priority Data massagingthe gums are described in which a pulsating jetof liquid is pressuremodulated, the modulation Aug. 16, 1968 Switzerland ..l2400/68 frequencybeing Substantially lower than the frequem cy of the pulsations, and themodulated pulsating jet is E directed against the surfaces to betreated. The p [58] Field of search' 66 224 tion frequency may be in therange of 600-6000 pul- 1 ses per minute, and advantageously above about3000, I to clean the teeth effectively. The modulation frequency may bein the range of 70-600 cycles per [56] References Cited minute, andadvantageously less than about 300, to

, UNITED STATES PATENTS massage the gums effectively- 3,547,110 12/1970Balamuth ..l28/62 A 11 Claims, 9 Drawing Figures ill ill

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PATENTEDflcI 10 I972 SHEET 1 BF 3 FIG. 1

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INVENTOR Michel A. Morer 1! v ATTORNEYS PATENTEDncr 10 I972 SHEET 2 BF 3FIG. 5

FIG. 4

FIG. 7

FIG. 6

INVENTOR M iche'l A. Morer BY 5M ATTORNEYS PATENTEDOEHOIHYZ sumanra FIG.8

INVENTOR Michel A; More? wh /gkfi ATTORNEYS 7 METHOD AND APPARATUS FORORAL HYGIENE BACKGROUND OF THE INVENTION necessitated the use of twodifferent tools, namely, the

toothbrush for cleaning the teeth, and various tools for massaging thegums. However, the human being, for various psychological reasons,devotes very little time to the practice of oral hygiene, using for themost part I only one tool (the toothbrush) and thus neglecting thegingival massage. So it has appeared highly desirable to provide thehuman being with a single tobl capableof performing both functions. Thusdevices'using the kinetic energy of water have been developed and madeavailable for home use.

I These a ate; can be classified in as ea'' aasz' (55 Q devices using acontinuous jet of water, and (b) devices using a pulsating jet of water.

Devices using a continuous jet of water do not provide a verysatisfactory solution because of: (l) the necessity of using a highwater pressure for satisfactory cleaning, which may exceed the thresholdof pain in the teeth and gums, these being very sensitive to highpressures, and (2) the lack of massaging efficiency, which can bedefined as an intermittent action of compression and release whichcannot be realized by a continuous mechanical effect.

Devices using a pulsating jet of water will perform both cleaning andmassaging to a degree, but encounter a problem of frequency. Effectivecleaning requires high frequency pulsation so as to allow theelimination of food residues with relatively low pressures which willnot exceed the threshold of pain. On the other hand, proper massage ofthe gums can be effected only with low frequencies which allow therebound of the gum tissue, this being the only valid physiologicalmethod which assures the elimination of veinous stasis and thecirculation of the arterial blood.

The gum, contrary to other surfaces of the body where a massage canstimulate the circulatory function, is a tissue with very littleelasticity because of its anatomical and histological structureinvolving lack of subjacent muscular tissue, terminal circulation, looseattachment which renders it easily infectable, rigid attachment whichreduces its elasticity, and its position directly on very hard organs(teeth and bone). Those anatomical factors do not allow, consequently,the use of high frequencies for massage such as can be used on othersurfaces of the body. The criterion for an effective massage of the gumsis the rebound which becomes obvious by the intermittent change of itscolor, alternately changing from pink to white and vice versa.

The well-know devices using pulsating jets of water,

operating at a single frequency, do not offer the possibility ofrealizing efficientlythe two desired operations. Since they commonlyhave high frequencies between 800 and 3,000 pulsations per minute, theyallow more or less good cleaning and a certain amount of massage byreflex action. However, the high frequency does not allow completerebound of the tissues and consequently the full value of the massage isnot obtained.

The present invention eliminates this incompatibility.

SUMMARY OF THE INVENTION In accordance with the invention a pulsatingjet of liquid is employed, and pressure of the pulsating jet ismodulated at a substantially lower frequency than that of thepulsations. The pulsation frequency can be relatively high in order toclean the teeth effectively. The modulation frequency is relatively lowin order to allow full rebound of the gum tissue and therefore effectivemassage. Thus, with independent choice of the two frequencies, both goodcleaning and effective massage may be obtained.

The actual frequencies employed may be selected to yield the mostsatisfactory cleaning and massaging under conditions expected to beencountered in use. Generally speaking, pulsating frequencies in therange of 600-6000 pulsations per minute may be used, and it is presentlypreferred to use frequencies of about 3000 per minute or more.Modulating frequencies may be in the range of -600 cycles per minute,and it is presently preferred to use frequencies between 200 and 300cycles per minute. It will be understood that the lower limit forpulsations and'the upper limit for modulation frequency are marginal,and would not be used simultaneously since the modulation frequencyshould be substantially lower than that of the pulsations. and in aratio of about 1: l0.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE SPECIFICEMBODIMENTS Referring to FIGS. 1-3, pump 1 is driven by motor 2 througha coupling mechanism 3 at an adequate speed for the frequency of the jetpulsations. Pump 1 contains a reciprocating piston such as shown in FIG.9, and mechanism 3 may be an eccentric pin and slot mechanism ofconventional construction. Cleaning liquid, usually water, is suppliedto the pump in any desired manner, here indicated as a reservoir 4.Water from the reservoir is supplied to inlet chamber 5 (FIG. 2) of thepump. Outlet chamber 6 connects through fitting 7 with flexible tube 8,at the end of which is nozzle 9. A check valve 1 1 is slidably mountedin a support 12 in the outlet chamber 6, and is biased by spring 13toward a closed position which restricts liquid flow through passage 14from the outlet chamber to the inlet chamber.

As so far described, the pump operates in a conventional manner. Thereciprocating piston (not shown in detail) communicates with the outletchamber 6. On its downward or suction stroke the check valve 11 opens(moves to the right) and water is drawn from inlet chamber throughpassage 14 into outlet chamber 6. On the upward or compression stroke,check valve 11.

moves to the left and a pulse of liquid under pressure is delivered tothe outlet tube 8 and thence to nozzle 9. The operation repeats tosupply a pulsating streamof water to nozzle 9.

Motor 2 also drives a reduction gear mechanism generally designated as15, and selected to furnish the desired modulation frequency. A link 16is driven by an eccentric pin 17 on the last gear of the reductionmechanism. The other end of link 16 is pivotally connected to a crankarm 20'attached to control rod 18. Consequently the reduction mechanismand link 16 causes crank arm20 .to oscillate, thereby angularlyoscillating control rod 18. Rod 18 is threaded at 19 so that the angularoscillation causes rod 18 to move axially back and forth a smalldistance. A pin 21 mounted at the end of rod 18 engages the check valve11, thereby controlling closure of the check valve.

Assuming that the check valve 11 is fully closed when rod 18 and itsattached pin 21 is in its left most position, pulses of maximum pressureare delivered to the outlet tube 8. As rod 18 and pin 21 move toward theright, the check valve 11 is prevented from fully closing, therebyproducing a by-pass or leak from outlet chamber 6" to inlet chamber 5and reducing the pulse pressure. As the control rod 18 oscillates, theclosure of check valve 11 cyclically varies to modulate the pressure ofthe pulses delivered to output tube 8-and nozzle 9.

Manual control of the overall pressure level is obtained by a controlrod 23 threaded into fitting 24. The inner end of rod 23 is adjacent anaperture 25 between inlet and outlet chambers. This establishes aby-pass or leak from the outlet chamber 6 to the inlet chamber 5 underthe control of rod 23.

FIG. 4 shows an unmodulated train of pulsations which would be producedin the outlet tube 8 if the modulation mechanism were not present. FIG.6 shows the same pulses on an expanded time scale. In general theyrisefrom a near zero pressure to a maximum pressure set by control rod23.

FIG. 5 shows the modulated jet. Here the pulsations vary from a maximumvalue at 27 to a minimum value at 28 in a cyclical manner. It will benoted that they minimum at 28 is substantially less than one-half themaximum at 27. The degree of modulation may be determined by appropriatedesign of the modulating mechanism. FIG. 7 is similar to FIG. 5, exceptthat the overall pressure level has been reduced by adjustment of rod23.

Referring now to FIGS. 8 and 9, a second embodiment of the invention isshown. I-Iere motor 31 directly drives piston 32 through an eccentricpin and slot mechanism 33. A second piston 34 is driven by the motorthrough areduction gear 35 and pin and slot mechanism 36. Consequentlypiston 32 is reciprocated at the frequency of the pulsations and piston34 is driven at the lower modulation frequency. Associated with piston32 is an inlet chamber 37 and an outlet chamber 38 with ;a checkvalve 39therebetween. The

arrangement for piston 34 is similar and includes check I is thecombination of the action of the two pumps,

namely, an addition or a subtraction of the pressure and the individualdischarge rates. Consequently the output to. tube 42 is a modulatedpulsating stream of water similar to that produced by the apparatus ofFIGS. 1-3. By properly selecting the diameters of the pistons the degreeof modulation may be predetermined. Thus the modulation may be 100percent if the individual discharge rates and the pressures of the pumpsare the same.

Manual control of the overall pressure level is obtained by means ofcontrol rod 43 which controls flow through the by-pass aperture 44between inlet and outlet tubes.

The apparatus described enables an efficient washing and massaging tobe. obtained.;The washing function uses the kinetic energy of the jetpulsations to take away the food residues wedged into the interdentalspaces, as well as for the cleaning of the subgingival marginsand theother generally unreachable tissues. The jet can be pulsated atdifferent overall pressure levels so as to comply with .treatmentrequirements. The pulsating frequency is advantageously high, forexample 3,000 pulsations per minute. Insofar as massage is concerned,the lower modulation frequency allows rebound of the gum tissues betweensuccessive maximum pressure peaks, thereby stimulating blood circulationin the gum tissues.

From an examination of the graphs, it is easily understandable thatbecause of the weak elasticity of the tissues, the pulsations which arerepresented in FIG. 4 will behave like a continuous jet on thesetissues,.while in FIG. 5 the modulating period at a lower frequencyallows the rebound of the tissues. In addition, the sensa tion is moreagreeable. Pressure peaks very close to each other (high frequencies)produce a sensation of uneasiness and tickling, which on a neurologicalplane produce an effect of irritation. Pressure peaks of greater spacing(low frequencies) do not produce such an irritation, but are agreeableto the user and hence assure more regular use.

The modulation frequency to obtain a massage by rebound is still moreefficient if it is nearly the same as the heart-stroke or one of itsmultiples. Accordingly, the frequency may be selected as a multiple ofthe heart-stroke frequency: 210 280 350 420 490 5 60 etc., cycles/min.

I claim:

1. Apparatus for oral hygiene which comprises a pump unit, a jet nozzle,and a conduit connecting said pump unit with said jet nozzle, said pumpunit including means for supplying a stream of spaced liquid pressurestream of liquid to said nozzle, a check valve between said chambersbiased toward a closed position which restricts liquid flow from outletto inlet chambers, a reciprocating piston for receiving liquid from saidinlet chamber through said check valve and producing pulsations in saidoutlet chamber, and means for cyclically varying the closure of saidcheck valve to thereby vary the pressure of the pulsations in saidoutlet chamber.

3. Apparatus in accordance with claim 1 in which said pump unit includesa pair of reciprocating pistons and respective inlet and outlet chamberstherefor, a pair of check valves between said inlet and outlet chambersrespectfully, means for connecting said inlet chambers in common to aliquid supply, means for connecting said outlet chambers in common tosaid nozzle, and means for reciprocating said pistons at substantiallydifferent frequencies.

4. Apparatus in accordance with claim 1 in which said pump unit isdesigned and adapted to cyclically reduce said peak pressures of thespaced liquid pressure pulses to a minimum pressure which is less thanone-half the maximum pressure thereof.

5. Apparatus in accordance with claim 4 in which the frequency of saidspaced liquid pressure pulses is in the range of about 600 6,000 pulsesper minute and the frequency of said cyclical reduction in the peakpressures thereof is less than about 300 cycles per minute,

6. Apparatus in accordance with claim 4 in which the frequency of saidspaced liquid pressure pulses is in the range of about 3,000 6,000pulses per minute and the frequency of said cyclical reduction in thepeak pressures thereof is less than about 600 cycles per minute.

7. In oral hygiene, the method of cleaning the teeth and massaging thegums which comprises forming a pressure-modulating pulsating jet ofspaced liquid pressure pulses which rise and fall between a low pressureand respective peak pressures and in which said peak pressures arecyclically reduced at a frequency substantially lower than the frequencyof the pulses, and directing said pressure-modulated pulsating jetagainst the surfaces to be treated.

8. A method according to claim 7 in which the peak pressures of thepulses of said pulsating jet are cyclically reduced to a minimumpressure which is less than one-half the maximum pressure thereof.

9. A method according to claim 8 in which the frequency of said pulsesis in the range of about 600 6,000 pulses per minute and the frequencyof said cyclical reduction in the peak pressures thereof is less thanabout 300 cycles per minute.

10. A method according to claim 8 in which the frequency of said pulsesis in the range of about 3,000 6,000 pulses per minute and the frequencyof said cyclical reduction in the peak pressures thereof is less th abot600c cl s er minute.

i i. A methoni a c rding to claim 8 in which the

1. Apparatus for oral hygiene which comprises a pump unit, a jet nozzle,and a conduit connecting said pump unit with said jet nozzle, said pumpunit including means for supplying a stream of spaced liquid pressurepulses through said conduit to said nozzle which rise and fall between alow pressure and respective peak pressures and means for cyclicallyreducing the peak pressures of said spaced liquid pressure pulsessupplied through said conduit to said nozzle at a frequencysubstantially lower than the frequency of said pulses.
 2. Apparatus inaccordance with claim 1 in which said pump unit includes an inletchamber for receiving liquid, an outlet chamber for supplying saidpulsating stream of liquid to said nozzle, a check valve between saidchambers biased toward a closed position which restricts liquid flowfrom outlet to inlet chambers, a reciprocating piston for receivingliquid from said inlet chamber through said check valve and producingpulsations in said outlet chamber, and means for cyclically varying theclosure of said check valve to thereby vary the pressure of thepulsations in said outlet chamber.
 3. Apparatus in accordance with claim1 in which said pump unit includes a pair of reciprocating pistons andrespective inlet and outlet chambers therefor, a pair of check valvesbetween said inlet and outlet chambers respectfully, means forconnecting said inlet chambers in common to a liquid supply, means forconnecting said outlet chambers in common to said nozzle, and means forreciprocating said pistons at substantially different frequencies. 4.Apparatus in accordance with claim 1 in which said pump unit is designedand adapted to cyclically reduce said peak pressures of the spacedliquid pressure pulses to a minimum pressure which is less than one-halfthe maximum pressure thereof.
 5. Apparatus in accordance with claim 4 inwhich the frequency of said spaced liquid pressure pulses is in therange of about 600 - 6,000 pulses per minute and the frequency of saidcyclical reduction in the peak pressures thereof is less than about 300cycles per minute.
 6. Apparatus in accordance with claim 4 In which thefrequency of said spaced liquid pressure pulses is in the range of about3, 000 - 6,000 pulses per minute and the frequency of said cyclicalreduction in the peak pressures thereof is less than about 600 cyclesper minute.
 7. In oral hygiene, the method of cleaning the teeth andmassaging the gums which comprises forming a pressure-modulatingpulsating jet of spaced liquid pressure pulses which rise and fallbetween a low pressure and respective peak pressures and in which saidpeak pressures are cyclically reduced at a frequency substantially lowerthan the frequency of the pulses, and directing said pressure-modulatedpulsating jet against the surfaces to be treated.
 8. A method accordingto claim 7 in which the peak pressures of the pulses of said pulsatingjet are cyclically reduced to a minimum pressure which is less thanone-half the maximum pressure thereof.
 9. A method according to claim 8in which the frequency of said pulses is in the range of about 600 -6,000 pulses per minute and the frequency of said cyclical reduction inthe peak pressures thereof is less than about 300 cycles per minute. 10.A method according to claim 8 in which the frequency of said pulses isin the range of about 3,000 - 6,000 pulses per minute and the frequencyof said cyclical reduction in the peak pressures thereof is less thanabout 600 cycles per minute.
 11. A method according to claim 8 in whichthe frequency of the pulses of said jet is about 10 times greater thanthe frequency of said cyclical reduction in the peak pressures thereof.